Trait LocalSpawnExt

pub trait LocalSpawnExt: LocalSpawn {
    // Provided methods
    fn spawn_local<Fut>(&self, future: Fut) -> Result<(), SpawnError>
       where Fut: Future<Output = ()> + 'static { ... }
    fn spawn_local_with_handle<Fut>(
        &self,
        future: Fut,
    ) -> Result<RemoteHandle<<Fut as Future>::Output>, SpawnError>
       where Fut: Future + 'static { ... }
}

Extension trait for LocalSpawn.

Provided Methods

fn spawn_local<Fut>(&self, future: Fut) -> Result<(), SpawnError>

where Fut: Future<Output = ()> + 'static,

Spawns a task that polls the given future with output () to completion.

This method returns a Result that contains a SpawnError if spawning fails.

You can use spawn_with_handle if you want to spawn a future with output other than () or if you want to be able to await its completion.

Note this method will eventually be replaced with the upcoming Spawn::spawn method which will take a dyn Future as input. Technical limitations prevent Spawn::spawn from being implemented today. Feel free to use this method in the meantime.

use futures::executor::LocalPool;
use futures::task::LocalSpawnExt;

let executor = LocalPool::new();
let spawner = executor.spawner();

let future = async { /* ... */ };
spawner.spawn_local(future).unwrap();

fn spawn_local_with_handle<Fut>( &self, future: Fut, ) -> Result<RemoteHandle<<Fut as Future>::Output>, SpawnError>

where Fut: Future + 'static,

Spawns a task that polls the given future to completion and returns a future that resolves to the spawned future’s output.

This method returns a Result that contains a RemoteHandle, or, if spawning fails, a SpawnError. RemoteHandle is a future that resolves to the output of the spawned future.

use futures::executor::LocalPool;
use futures::task::LocalSpawnExt;

let mut executor = LocalPool::new();
let spawner = executor.spawner();

let future = async { 1 };
let join_handle_fut = spawner.spawn_local_with_handle(future).unwrap();
assert_eq!(executor.run_until(join_handle_fut), 1);

Dyn Compatibility

This trait is not dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety", so this trait is not object safe.

Implementors

impl<Sp> LocalSpawnExt for Sp

where Sp: LocalSpawn + ?Sized,